Suppression of AGO2 by miR-132 as a determinant of miRNA-mediated silencing in human primary endothelial cells.
Suppression of AGO2 by miR-132 as a determinant of miRNA-mediated silencing in human primary endothelial cells.
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DOI：
10.1016/j.biocel.2015.10.006
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发表时间：
2015-12
期刊：
影响因子：
--
通讯作者：
Lagos D
中科院分区：
文献类型：
--
作者：
Leonov G;Shah K;Yee D;Timmis J;Sharp TV;Lagos D
miR-132的丰度范围从大脑中的组成性高（这是神经元发育和功能所必需的）到造血细胞和内皮细胞中的诱导表达（它控制血管生成和免疫激活）。我们发现，miRNA介导的基因沉默和miRNA生物发生的核心蛋白AGO2的表达受到miR-132的负调控。在HeLa细胞中，我们证明了miR-132与AGO2 mRNA 3'UTR相互作用，抑制AGO2表达和AGO2依赖性小rna介导的沉默。同样，miR-132过表达导致原代人真皮淋巴内皮细胞（HDLECs）中AGO2抑制。在HDLECs的肉豆蔻酸酯phorbol acetate （PMA）激活过程中，miR-132以creb依赖的方式被诱导，miR-132的抑制导致AGO2表达增加。与AGO2在维持miRNA表达中的作用一致，miR-132抑制AGO2会影响miR-221和miR-146a的稳态水平，这两种miRNA分别参与血管生成和炎症。我们的数据表明，mirna沉默机制在原代细胞激活过程中通过miR-132直接抑制AGO2受到自动调节。
The abundance of miR-132 ranges from constitutively high in the brain where it is necessary for neuronal development and function, to inducible expression in haematopoietic and endothelial cells where it controls angiogenesis and immune activation. We show that expression of AGO2, a protein central to miRNA-mediated gene silencing and miRNA biogenesis, is negatively regulated by miR-132. Using HeLa cells, we demonstrate that miR-132 interacts with the AGO2 mRNA 3′UTR and suppresses AGO2 expression and AGO2-dependent small RNA-mediated silencing. Similarly, miR-132 over-expression leads to AGO2 suppression in primary human dermal lymphatic endothelial cells (HDLECs). During phorbol myristate acetate (PMA)-activation of HDLECs, miR-132 is induced in a CREB-dependent manner and inhibition of miR-132 results in increased AGO2 expression. In agreement with the role of AGO2 in maintenance of miRNA expression, AGO2 suppression by miR-132 affects the steady state levels of miR-221 and miR-146a, two miRNAs involved in angiogenesis and inflammation, respectively. Our data demonstrate that the miRNA-silencing machinery is subject to autoregulation during primary cell activation through direct suppression of AGO2 by miR-132.